reversion question help!!!!!!!
 

Here is the situation. I have a new motor its a 638" bbc, dart block, intake and heads. the headers are cmi split tops. the cam is from comp but it was a teage specific cam. the specs on the cam are 258* intake 266* exhaust* @.050" on a 114 lobe seperation. the headers have no drop at the tail pipes and the are injected at the tips. the problem is is that I keep mixing water and oil. I pressure checked the block it checks out ok so at 40 psi I have no loss of pressure. the headers check out ok at 35 psi but the 1,3,5,7 cylinder side of the motor has water in all 4 header tubes after running it at idle for a few minutes. there is no water in the other header. I am sure that the water in the oil is coming from the exhaust but why would only one side of the motor have reversion? the tail pipe on this side is the longer of the 2 if that matters. HELP!!!!! I am out of ideas and patience.

It doesn't make sense to me just being on the one side if it was to be reversion. You certain everything is plumbed properly?

well too be perfectly honest no I am not. the boat is actually at a shop and I have been there working on it so I can get it done lol. how could the cooling system be being improperly plumbed cause these symptoms?

Are you sure the intake is sealed good

Seems unlikely that the intake would put water in all 4 intake ports. Thats a pretty mild cam to revert water from dry tailpipes. I'm voting for a problem above the joint in the exhaust. If you are certain that there are no leaks in any of the pipes, than it must be reversion. In that case, have some spacers made to raise the collectors and tailpipes and get some downward angle.

maybe I wasnt clear. there is water in all 4 header tubes but only on one side???????? the other side has no water in the header tubes. the oil actually looks like it is getting worse every time its changed. the headers were tested with the tops on them with no psi loss. I have not tested the tail pipes but they are dry to the tip.

Free Water Maker!
 

From what I read here it does not seem possible or probable that only one side of this engine would expierence reversion. I have seen horizontal exhaust systems (no drop down angle) have water lay in the tubes and get sucked back into a normally aspirated engine with a mild cam, but it should be happening on both sides of the engine.
I would take another look at the head gasket seal on that side. My expierence with 600 plus cubic inch big blocks means bore sizes of 4.600" or larger and that leaves so little head gasket around some parts of the head you could be looking at water coming from one or more cylinders getting out the exhaust, up to the header horizontal and being pulled into the other cylinders on that side of the engine. Just a thought but if you've thoroughly check out the headers and tips for leaks then the water is got to be coming from somewhere on that side of the engine.

Best Regards,
Ray @ Raylar

here is a little more info and a slight recap of the situation.
the leak down was 3 to 5% across all 8 cylinders. the compression test shows 170-180#s. I did dump the water overboard this afternoon and it still has water in the oil. I pulled the intake and it is concentrated at the front corners of the intake to the point that it looks like an actual milkshake. its very thick in the 2 corners. I cant see why a pressure test wouldn't reveal an intake leak but I believe thats what it is. I also pulled the heads off and the head bolts were no longer torqued to what I had them. the short bolts were as loose as 60 pounds and the long bolts were averaging 70-75 pounds. I believe that the head bolts may be a little long they are arp bolts but the dart block has blind holes. I am thinking that the heads will torque when the cometics are new but when the settle in I believe that the head bolts are bottoming out before I can get crush on the gaskets. I ordered new cometics, new intake gaskets and new head bolts that are specific to the dart heads. whats different about the bolts I dont know but they are different. my theory as simple as it may sound is that the heads are lifting allowing the compression to push water into the front corner of the intake. sound plausible? The reason I think this is because it doesn't present itself when checking with psi it only does it when its running. 170-180 pounds of cylinder pressure its certainly enough to push water out of a non seated gasket I think???? thanks for all the input guys.I am about to throw in the towel lol. I am over 15k into this new motor and its never been in the water.

water
 

I feel bad for your situation and sicereley hope the best for you and solve your problem soon. Just another thought though after thinking about this a little more. I'm not for sure what exhaust you have however is it possible when pressure checking them they check out fine under room temps but is it possible also that at over 1,100 degree exhaust temps a crack might/could expand and allow the reversion and even transfer to the other cylinders on the same side.

I really feel this is an exhaust issue. Do you have any other exhaust available to test even if it is only on the bad side. Even if you have to use flex tubing to get it out the transom.

With all the test and process of elimination you have done I am completely baffled. I wish you the best of luck and if anything else comes to mind I'll pass it on for what ever it's worth.

Stay tuned,
John

well I changed the head gaskets and the intake gaskets and guess what......the first 10 minutes the oil was perfect so I changed it and ran it again for 10 minutes and it milked the oil. the only changes between the two 10 minute sessions is that The timing was changed and the idle was lowered to 1000 rpm's. I am out of ideas and patience. anyone have any other suggestions?

Has the intake manifold been checked to make sure it mates perfectly to the head, especially near the water jackets? I agree with Raylar that it wouldn't seem that the exhaust on only one side would leak and not the other, but I also see Getrdone's point about there being small cracks and when heated they seep more. Just to rule it out, I would check the intake mating surface and then try a different exhaust.

Reversion gets worse when the idle is lowered. Loosen the tailpipe at the header joint and see if water drips at idle. I ran the same cam and water poured out when I tried that. Had to go to dry pipes. The fact that your tailpipes have no drop might be it.

yes the intake appears to fit the heads perfectly so I don't think that's it. the headers were my other motor 4 weeks ago and were fine with no leaks. it hasn't been cold so I think I can rule out any cracks. I do have a little bigger motor and a slightly bigger cam (little more duration)but other than that these are the same heads and intake that were in my 632. when I took the heads off to replace the head gaskets I sent them back to the machine shop and had them tested and they are fine. I am thinking it may be reversion as I can see some water puddling up in the tail pipes and since they are dry to the tip they shouldn't be wet there?

Try and run it at between 2000 and 2500 for 15 minutes or so, then check. I can't imagine that reversion would be an issue at this RPM however not certain. If there is no indication of water I would say it's reversion.

Just a thought here, couple of questions again, how is your exhaust system configured from the risers back and what headers do you have? what type of vertical fall between the riser and the tips?
also, do you know the LSA on your camshaft grind in the engine?

Best Regards,
Ray @ Raylar

my headers are cmi split tops. they bolt together with a 4 bolt flange at the riser. then they go back to a v band clamp for the tail pipes which are dry to the tips. these headers were on my other motor 4 weeks ago with no issues. the cam has a 114 lobe seperation. the headers do not have any fall. the tail pipe is basically parallel to the motor. in other words the tail pipes exit over the transom and through the hatch like a jet boat. the cam isnt really what most would consider "big" at .647 lift intake and exhaust. the duration @.050 is 258 intake and 266 exhaust and again its on a 114 lsa. I have a pretty extensive drag racing background so I am not a complete idiot but this thing is whipping me lol. can timing contribute to reversion? such as having too much initial timing? in other words if the initial timing was set at 36 degrees I am not sure what my msd distributor advances at degree wise but I am sure the shop that put the motor back in had the base timing at 38 degrees and thats waaaaaay too much as my 632 only liked about 36 total. I just found that out this morning and also that the cam wasn't degreed in and I now think thats the problem. thats why the engine needed 38 degrees of timing to idle any lower than 1100 rpm.

What type of distribution pump/thermostat system are you running? The water in one side could be caused by a cold water bypass, possibly favoring one side and condensing in the exhaust. I have had engines that would cause a milkshake look inside the valve cover before the oil got up to temp.

I find it hard to believe that one CMI would be bad, considering the money for those. But getrdunn might be on to something. After they heat up they might open a crack or leak.

Belay my last. sorry I missed some post's.


My engine builder took the springs out of the MSD and locked it @ 29 degrees advance. I think? And considered a retard box to try to prevent reversion. ( I can't remember for sure what it was locked in at.)

comp cams lobe sep. 114.0 230 236exh @ .050duration
lift @ .613 .608exh Stock exhaust manifold. Still reversion I'm looking @ EMI or the sort.

the motor is going to stotler race engines in the morning. I am tired of screwing around with the current situation. the cam was not degreed in and I believe that is is actually installed 4 degrees retarded and thats why the motor will only idle with 38 degrees of initial timing. I believe cam timing is my problem now. the cam is a teague spec comp cam and the fellow at teague said the cam needs to be installed 4 degrees advanced and it was not installed that way. I will update as I know and I really appreciate all the advice guys.

I do not have a pump on the motor I only have the seawater pump. this is not only in the valve covers it looks like a vanilla milkshake when you drain the oil. the weird part is that its not really showing much of a volume change? I know a little water will cause some discoloration but my oil is emulsified.

Water in exhaust is always a bit of a problem!
 

I would still recommend what Patriyacht is saying that the horizontal only tailpipes on those headers are going to cause a water and mist issue during overlap into that engine. If you cannot get some drop to the tips then for all means run cooled tips with the water exit at the tip only even with your cam dialed back in where it should be.

Just my two cents here.
Hope your troubles are over.

Best of Luck
Ray @ Raylar

the tailpipes are dry all the way to the tips so I am not surte what you are saying. I had these same headers on my other motor with pretty much the exact same setup with the exception being the cubic inches being a little more on the new motor(22 ci bigger) and the cam in the new motor has a little more duration.

Ok I got an idea.... it will take a few hours but this should rule out the headers completely.

Remove the headers and swap them onto the other motor. Once you get done swapping both motors, fire them off and see if you have this problem with the other motor on the same header. If not, you have ruled out the headers as the cause and you have singled it out that it is the engine that is the problem.

This should work. I think I read correctly where you said the other motor has no issues at all, right?

yes my other motor had zero issues with reversion. The crank broke after the main cap decided to take a brake lol. this is a single engine application but I am going to try another set of headers once I get the motor back from stotler.

What was the fix......
 

So Lake Speed, What was the fix???? I have almost the same problem.. Thanks